You need to use Planck's law:
E = h·υ = (h·c)/λ
Without making all the calculations, a fraction is bigger than another when the denominator is smaller. Therefore you need to find the smallest wavelength (λ) which is 450nm.
You could also be helped by colors: in order of decreasing energy, you have blue - green - yellow - red.
In any case, the correct answer is a).
To determine the diameter of the earth in metres first multiply the original value by 2.
6378 X 2 = 12 756 km.
Then convert km - m
1 km = 1000 m
12 756 km = ? m
12 756 • 1000 = 12 756 000 = 12 756 000 m or 1.2756 X 10 ^ 7 m
The final solution for the diameter is 1.2756 X 10 ^ 7 m.
Answer:
The velocity of water at the bottom, 
Given:
Height of water in the tank, h = 12.8 m
Gauge pressure of water, 
Solution:
Now,
Atmospheric pressue, 
At the top, the absolute pressure, 
Now, the pressure at the bottom will be equal to the atmopheric pressure, 
The velocity at the top, 
, l;et the bottom velocity, be 
.
Now, by Bernoulli's eqn:
where
Density of sea water, 
Quantitative because it tells you how many wheels
13 is the mode because it is the number that appears most often
:)
